MicroRNA regulation of biological mechanisms

描述（由申请人提供）：我们最近对一类小的非编码rna microRNAs的机制和生物学有了很大的了解。这类引人注目的rna占人类基因组基因的1%，它们抑制蛋白质编码基因的表达。在动物物种中，这主要是通过在其3'非翻译区域中包含互补序列的信息中注意蛋白质合成来实现的。尽管难以估计microRNA调控的程度，但有4 - 20%的蛋白质编码基因可能直接受microRNA调控。模式生物的遗传研究支持microrna在细胞和有机体生物学中发挥选择性作用的观点。我们感兴趣的是了解microRNAs如何特异性抑制其靶基因以及这种调节的生物学后果。为此，我们开发了一种通过原位杂交检测整个果蝇组织和胚胎中单个microrna的方法。我们将评估78种已知果蝇微rna在眼睛发育过程中的表达模式。将评估眼部中调节microRNA表达的上游调控途径，并将其与已知的这些途径的生物学功能相关联。我们将使用microRNA基因诱变来确定microRNA是否参与这些生物过程。计算机和分子遗传学方法的结合将用于识别和表征microRNA抑制的直接靶点，并研究microRNA介导的翻译抑制特异性的调控机制。我们的目标是破译microRNA在人体不同组织中关于靶标和生物特异性的调控规则。microRNAs的联合作用可能影响许多人类基因的表达，microRNAs的错误调控可能是复杂疾病现象的基础，如癌症的易感性和进展。

DESCRIPTION (provided by applicant): We have learned a great deal recently about the mechanism and biology of a class of small non-coding RNAs called microRNAs. This remarkable class of RNAs constitute 1 % of the genes in the human genome, and they repress the expression of protein-coding genes. This is achieved in animal specieis primarily by attenation of protein synthesis from messages which contain complementary sequence in their 3' untranslated regions. Although it is difficult to estimate the extent of microRNA regulation, from 4 - 20% of protein-coding genes might be directly controlled by microRNAs. Genetic studies in model organisms support the notion that microRNAs play select roles in cell and organismal biology. We are interested in understanding how microRNAs specifically inhibit their target genes and the biological consequences of this regulation. To this end, we developed a method to detect individual microRNAs in whole Drosophila tissues and embryos by in situ hybridization. We will evaluate the expression patterns of the 78 known Drosophila microRNAs during eye development. The upstream regulatory pathways that regulate microRNA expression in the eye will be evaluated, and correlated to known biological functions of these pathways. We will use microRNA gene mutagenesis to determine if microRNAs are involved in these biological processes. A combination of in silico and molecular genetic approaches will be used to identify and characterize direct targets of microRNA repression, and to investigate the mechanism(s) governing the specificity of microRNA- mediated translational repression. Our goal is to decipher the rules of microRNA regulation regarding target and biological specificity in diverse tissues of the body. The combined effects of microRNAs may affect the expression of many human genes, and misregulation of microRNAs may well underlie complex disease phenomena such as cancer susceptibility and progression.